Heat Wave to Bring Triple Digit Heat to the Southwest into the Weekend
It’s that time of year. Highs in the triple digits are in the forecast across the Desert Southwest this weekend in what is likely to be the first major heat wave of the year for the region, which is expected to last through much of the following week. Heat alerts have already been issued in coastal Southern California and around Phoenix.
High pressure will begin to build at the surface this weekend before a large ridge of high pressure builds in the middle and upper levels of the atmosphere early next week. This large upper level ridge, centered over Arizona and Northern Mexico, could even bring temperatures of 110° or more to the infamously hot Death Valley in California, by the middle of next week.
The heat is also expected to spill over into areas west of the mountains in Southern California by Friday, due to offshore winds, with areas like Los Angeles and Riverside climbing into the 90s.
Highs will be 10-15 degrees above average for many in the region and several records could be broken on Friday. Temperatures will continue to climb this weekend.
For many, the first triple digit mark of the year will fall within a week of the average first on record, however, heat has been a bit slower than normal to arrive in many desert locations, due to a cooler and relatively wet pattern during March and April.
The first 90°F+ day in #Phoenix is expected on Wednesday, more than three weeks later than our "normal" date of March 31st. However, our first 100°F+ day will likely occur within seven days of our first 90° day, marking only the 5th time that will have occurred since 1896. #azwx pic.twitter.com/9j1TMeaiRW
— NWS Phoenix (@NWSPhoenix) April 20, 2020
Phoenix is expected to record its first 90 degree high of the season Wednesday, even though the average date for hitting that mark is March 31st! This would be the latest first 90 degree day since 1995. If Phoenix manages to hit 100 degrees by the weekend, it will join less than a handful of other seasons when the first 100 degree day arrived just days after the first day in the 90s. Check out this article for more on the climatology of 100 degree days in Phoenix.
Palm Springs, California, which averages their first triple digit high of the year about a week before Phoenix, has also yet to record a 90 degree high (hitting 89 twice). It too could see its first 90 degree and 100 degree day fall within a few afternoons of each other.
What about the hottest place on earth? Death Valley, also lagging behind with extreme heat this season, is expected to record their first 100° temperature on Wednesday, which would be more than a month behind its average, according to the National Weather Service.
Similar to Phoenix and Palms Springs, Death Valley could hit two heat thresholds within a short period of time. Its first 110° + day is forecast for next Tuesday, which would come less than a week after its first 100° day and nearly four weeks ahead of average.
Even though these area will likely experience their first 100 degree days of the year in the days ahead, it won’t be the first in the lower 48 this year. Laredo, Texas, has already recorded highs in the triple digits several times, the first coming in late March.
The extended forecast isn’t looking promising for those hoping to avoid the heat of summer even longer, at least in the Southwest. The Climate Prediction Center gives the region a great chance to continue to see above average temperatures through the end of April and the first week of May.
When extreme heat is in the forecast, be sure to take precautions to avoid heat related illness. Stay hydrated by drinking plenty of water and avoiding alcoholic beverages. Work or recreate during the cooler parts of the day, such as the early morning or in the evening. If you have to be outside during the afternoon hours, take plenty of breaks in the shade, wear light colored clothing, and learn to recognize the signs of heat stroke.